Method for manufacturing inflatable bladders for use in footwear and other articles of manufacture

ABSTRACT

The present invention is a method for manufacturing inflatable bladders for use in articles of manufacture. The method includes the steps of providing a first polymer film, applying a curable release coating to the polymer film in a pattern that corresponds to the configuration of the inflatable bladder, curing the release coating to the first polymer film, providing a second polymer film with the first polymer film to form a layered element such that the release coating is disposed between the polymer films, positioning the layered element between two plies of material, applying heat and pressure to adhere the polymer films together except in the area where the release coating has been applied to form an inflatable compartment surrounded by a sealed perimeter, and removing the plies of material from the adhered first and second polymer films.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.12/903,129, filed Oct. 12, 2010, the disclosure of which is incorporatedherein in its entirety by reference thereto.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to methods for manufacturing inflatablebladders and also to inflatable bladders and footwear and other articlesof manufacture which include such inflatable bladders.

2. Background Art

Inflatable articles of manufacture or bladders for use in inflatablearticles of manufacture have been known for decades. Such articles ofmanufacture include inflatable air mattresses and pillows, inflatablelife preservers and rafts, and athletic equipment. In the field ofathletic equipment, inflatable bladders have been incorporated in theinterior of balls (e.g., basketballs, footballs, soccer balls, etc.), aswell as in apparel and protective equipment such as baseball and boxinggloves, helmets, chest protectors and footwear. When utilized infootwear, an inflatable bladder may be used to provide customizedcushioning to the wearer's foot and to enhance fit. In some instances,an inflatable bladder may take the place of a lacing system to securethe shoe to the foot of the wearer. Inflatable bladders may also be usedin the sole of a shoe to provide cushioning to the bottom of thewearer's foot and to absorb impact forces from walking, running andjumping.

U.S. Pat. No. 7,278,445 discloses a Shoe Having an Inflatable Bladder,the disclosure of which is incorporated herein by reference in itsentirety.

U.S. Pat. No. 5,113,599 to Cohen et al. (the '599 patent) discloses anathletic shoe having, an inflatable bladder. This patent discloses avariety of inflatable bladder configurations for use in the tongue, onlateral and medial sides, around the ankles, beneath the foot, or in theentirety of the shoe. The bladder of the patent is formed from a firstthermoplastic urethane (TPU) film and a co-extensive second TPU film.The first and second films are attached to each other along pre-definedweld or pattern lines. A peripheral weld line of the bladder creates asealed bladder compartment or chamber and prevents air from escapingfrom the bladder. The first and second films are further attached toeach other at a number of circular points or interior weld lines tocontrol the thickness of the bladder to prevent undesired “bulging”,which could cause discomfort to the wearer or inhibit proper fit.

The first and second films of the bladder of the '599 patent are weldedtogether using radio frequency (RF) or dielectric welding. RF ordielectric welding uses high frequency radio energy to agitate themolecules of thermoplastic materials to a point where they melt and weldtogether to form a strong bond. To weld the bladder of the '599 patent,the coextensive films are placed between a brass die (having raisedareas representing the desired peripheral, circular and interior weldlines) and a platten on an RF machine. After bringing the brass die andRF platten into contact with each other, the RF machine is activated andthe first and second films are bonded to each other only at the raisedareas on the brass die to form the peripheral, circular and interiorweld lines. Upon completion of the welding step, the inflatable bladderis die-cut from the remainder of the coextensive first and second filmsand assembled into the shoe as appropriate by adhesives, conventionalstitching or other fastening means. The first and second films of the'599 patent may also be adhered to each other by conventionally heatedand appropriately patterned brass dies or by application of chemicaladhesives or bonding agents suitable for use with thermoplastic films.

The patent further discloses inflation of the bladder by a pumppermanently affixed to the bladder using the RF welding techniquedescribed above or any other sealing method appropriate for use with thefilms thereof. Alternatively, the bladder may be inflated by anoff-board pump connectable to an inflation/deflation valve, also affixedto the bladder in a location easily accessed by the wearer. Other pumpsand valves, suitable for use with inflatable bladders for footwear, aredisclosed in U.S. Pat. Nos. 5,074,765 and 5,144,708.

While manufacture of an inflatable bladder using RF welding requires noadhesives or additional materials and has the advantages of precisepatterning, decreased heat-degradation in areas of the film adjacent toweld lines and strength of seal, it is costly and time consuming tomachine or chemically etch the brass dies for the inflatable bladderpatterns, particularly where an article of manufacture is produced in alarge range of sizes and in multiple configurations. Conventionallyheated brass dies are also expensive to machine, while chemical adhesionis messy and requires cure time in controlled environments. Moreover, RFwelding techniques are extremely sensitive, require that the films besufficiently thick to prevent excessive melting of the film (which couldcause a breach of the bladder), and often result in finished bladdersthat “curl” along their edges (which can complicate their assembly intoarticles of manufacture such as footwear).

Thus, it is desirable to provide a method for manufacturing inflatablebladders for use in footwear and other articles which is relativelyinexpensive, time efficient and allows for the manufacture of a varietyof bladder configurations and sizes, utilizing a process and materialsresulting in little to no interruption or delay in the manufacturingprocess.

BRIEF SUMMARY OF THE INVENTION

The manufacturing method of the present invention is advantageous overthose known in the art, in that it is simpler, can be semi-continuous orsemi-automatic in nature, easily modified to permit manufacture of avariety of bladder configurations, and more economical by avoiding theneed for expensive configuration-specific, brass-machined tooling. Inone aspect of the present invention, a method for manufacturing aninflatable article comprises the steps of providing a first polymer filmhaving an inner side and an outer side, applying a curable releasecoating to the inner side of the first polymer film in a pattern thatcorresponds to the configuration of an inflatable compartment of aninflatable bladder, cuing the release coating to the inner side of thefirst polymer film by the application of ultra-violet light, providing asecond polymer film having an inner side and an outer side with thefirst polymer film to form a layered element, such that the releasecoating is disposed between the inner side of the first polymer film andthe inner side of the polymer film, positioning the layered elementbetween a first ply of material and a second ply of material, applyingheat and pressure to the first and second plies of material positionedabout the layered element to adhere the first polymer film to the secondpolymer film except in the area where the release coating has beenapplied to the inner side of the first polymer film to form aninflatable compartment surrounded by a sealed perimeter, and removingthe first and second plies of material from the adhered first and secondpolymer films. The curable release coating may be silicone fortified.The curable release coating may be applied to the inner side of thefirst polymer film by screen printing. The first and second plies ofmaterial may be polytetrafluoroethylene-coated, fiberglass-reinforcedcloths. At least one of the first and second plies of material may betextured. The applying heat and pressure step may be accomplished byrotary lamination. The method may farther comprise the step of cuttingalong the sealed perimeter to form an inflatable bladder having a sealedattachment margin and incorporating the inflatable bladder into anarticle of footwear by attaching the inflatable bladder to the articleof footwear at the attachment margin. The method may farther comprisethe step of coupling an inflation device and a deflation device to theinflatable bladder. One of the first or second polymer films may be alaminate comprised of a polymer layer and a substrate.

In another aspect of the present invention, a method for manufacturingan inflatable bladder comprises the steps positioning a barrier materialbetween a first film and a second film in a configuration thatcorresponds to the shape of an inflatable compartment of the inflatablebladder, positioning the first and second films with the barriermaterial positioned thereinbetween between a first ply of material and asecond ply of material, adhering the first film to the second filmexcept in the vicinity of the barrier material to form the inflatablebladder having the inflatable compartment surrounded by a sealed,continuously substantially flat perimeter, and removing the first andsecond plies of material from the inflatable bladder. The method mayfurther comprise the step of incorporating the inflatable bladder intoan article of footwear by securing the inflatable bladder to the articleof footwear at the perimeter of the inflatable bladder. The barriermaterial may be a paint, ink, paper, textile, photosensitive agent,wire, foil, or particulate. The barrier material may be a curablerelease coating, and the step of positioning the barrier materialbetween the first film and the second film may include the substep ofapplying the release coating to the first film, curing the releasecoating to the first film, and sandwiching the cured release coatingbetween the first and second films. The release coating may be appliedto the first film using a screen, template, or stencil. The releasecoating may be cured by the application of ultra violet light. The firstand second plies of material may be polytetrafluoroethylene-coated,fiberglass-reinforced cloths. At least one of the first and second pliesmay be textured. The adhering step may be accomplished by rotarylamination, by heated pressing between platens, or by application ofvacuum and heat. The method may further comprise the step of coupling aninflation device and a deflation device to the inflatable bladder. Atleast one of the first or second films may be a laminate comprised of apolymer layer and a substrate. The barrier material may include at leasttwo release coatings. Where two release coatings are provided, the stepof positioning the barrier material between the first film and thesecond film may include the substep of applying a first release coatingto the first film, applying a second release coating to the second film,curing at least one of the release coatings, and sandwiching the releasecoatings between the first and second films. The release coating appliedto the second film may be a discontinuous coating.

In yet another aspect of the invention, an inflatable article offootwear comprises a sole and an upper having an inflatable bladderattached to the sole. The inflatable bladder comprises a first film, arelease agent applied and cured to the first film in a pattern thatcorresponds to the shape of an inflatable compartment of the inflatablebladder, a second film adhered to the first film such that said releaseagent is disposed between the first film and the second film and thefirst film and the second film do not adhere to each other in thevicinity of the release agent thereby forming the inflatable compartmentwith a peripheral edge, whereby the inflatable bladder is devoid ofraised weld lines or raised adhering seams and wherein at least aportion of the exterior surface of the inflatable bladder is textured.Substantially all of the exterior surface of the inflatable bladder maybe textured. The textured exterior surface of the inflatable bladder maycorrespond to the texture of a ply of textured material that waspositioned adjacent to the exterior surface of at least one of the firstfilm or the second film while the first and second films were adhered toeach other. The ply of material may be polytetrafluoroethylene,fiberglass-reinforced cloth. The inflatable bladder may include asubstantially flat, adhered attachment margin extending from theperipheral edge of the inflatable compartment to an edge of theinflatable bladder to facilitate attachment of the inflatable bladder tothe upper of the article of footwear. The cured release agent may besilicone fortified and cured by the application of ultra violet light.At least one of the films may be a polymer bonded to a substrate. Thearticle of footwear may comprise an inflation device and a deflationdevice.

In still another embodiment, an inflatable article of footwear comprisesan upper, a sole attached to the upper, and an inflatable bladderattached to the article of footwear. The inflatable bladder comprises afirst single-layered film having an inner surface and a textured outersurface, a release agent applied and cured to the inner surface of thefirst single-layered film in a pattern that corresponds to the shape ofan inflatable compartment of the inflatable bladder, a secondsingle-layered film having an inner surface and a textured outer surfacedisposed in facing relationship with and adhered to the firstsingle-layered film such that the release agent is disposed between theinner surface of the first single-layered film and the inner surface ofthe second single-layered film, the release agent preventing the firstsingle-layered film from adhering to the second single-layered film inthe area where the release agent is applied to form the inflatablecompartment of the inflatable bladder. The texture of the outer surfacesof the first and second single-layered films may be imparted thereto bya woven material disposed adjacent to the outer surfaces of the firstand second single-layered films during adherence of the firstsingle-layered film to the second single-layered film.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form a partof the specification, illustrate the present invention and, togetherwith the description, further serve to explain the principles of thepresent invention and to enable, a person skilled in the relevant art topractice the same.

FIG. 1 is a depiction of the steps of the method of the presentinvention for manufacturing inflatable articles or bladders for use ininflatable articles;

FIG. 2 is a negative image of an inflatable bladder design orconfiguration as formed on a printing screen;

FIG. 3 is a depiction of the step of applying, a barrier material to afirst film of the method using the printing screen of FIG. 2;

FIG. 4 is a depiction of the transferred barrier material positionedbetween the first and second films of the method;

FIG. 5 is a depiction of the first and second films of the method assealed together;

FIG. 6 is a depiction of an inflatable article or bladder made inaccordance with the method of the present invention;

FIG. 7 is a depiction of an alternate embodiment of the step forapplying a barrier material to a first film;

FIG. 8A is an exploded depiction of how to provide a fitment;

FIG. 8B is a depiction of the fitment as adhered to first and secondfilms;

FIG. 9 illustrates the steps of a method according to an embodiment ofthe present invention for manufacturing inflatable bladders for use infootwear and other articles of manufacture;

FIG. 10 is a top plan view of a first film of the method of FIG. 9 witha release coating applied thereto;

FIG. 11 is a plan view of a basic screen printing process;

FIG. 12 is a top plan view of a layered element of the method of FIG. 9comprising the first film, with the release coating cured thereto, and asecond film;

FIG. 13 is a top plan view of the layered element of the method of FIG.9 positioned between a first ply and a second ply;

FIG. 14 is a side schematic view of a rotary lamination machineaccording to an embodiment of the present invention;

FIG. 15 is a top plan view of the adhered first and second films, withthe release coating cured thereinbetween, showing the texture impartedto the films by the first and second plies of material according to anembodiment of the present invention;

FIG. 16 is a top plan view of a valve body according to an embodiment ofthe present invention;

FIG. 17 is a partial top plan view of an inflatable bladder according toan embodiment of the present invention, with part of the bladdercut-away to provide for attachment of an inflation and deflation device;

FIG. 18 is a perspective view of the valve body and inserted clothstrand according to an embodiment of the present invention;

FIG. 19 is a top plan view of a finished inflatable bladder according toan embodiment of the present invention, with an attached inflationdevice and deflation device, manufactured in accordance with the methodof FIG. 9; and

FIG. 20 illustrates the steps of a method according to anotherembodiment of the present invention for manufacturing an inflatablebladder.

DETAILED DESCRIPTION OF THE INVENTION

It is desirable for inflatable articles of manufacture or bladders to bedurable, as well as quick, easy and inexpensive to manufacture. Thepresent invention seeks to reduce the cost and time typically associatedwith the manufacture of inflatable articles or bladders for use ininflatable articles of manufacture, by simplifying the manufacturingprocess and avoiding the need for brass tooling, which can be expensiveand time-consuming to machine or form, as well as to change-out, topermit the manufacture of inflatable articles or bladders havingnumerous sizes and configurations.

While conventional bladder manufacturing methods rely on toolingspecific to the configuration of the bladder to weld or seal two or morefilms together to form inflatable areas or compartments, the method ofthe present invention employs a barrier material (also referred toherein as a release coating or agent) applied to one of the films (orboth of the films), in accordance with a pre-defined or customizedpattern, to prevent the films from adhering together to createinflatable areas or compartments, when heat and/or pressure are appliedthereto. The barrier material can be easily applied to either of thefilms, in various configurations, to permit manufacture of an inflatablearticle or bladder inexpensively, quickly, essentially continuously andwith a high degree of manufacturing flexibility.

As shown in FIG. 1, a method of the present invention generallycomprises the steps of 1(a) providing a first film, which for mostapplications will be impervious to the fluid used to inflate the bladderor inflatable article of manufacture, 1(b) applying a barrier materialto a first side of the first film, 1(c) providing a second film with thefirst film such that the barrier, material is disposed between the firstfilm and the second film, 1(d) adhering the first film to the secondfilm to form a sealed peripheral area, except in the area where thebarrier material has been applied, to form at least one inflatablecompartment, and optionally, 1(e) cutting along the sealed peripheralarea to form an inflatable article or inflatable bladder having a sealedperipheral edge for use in an article of manufacture. It is alsoenvisioned that the barrier material could be applied to the second filmor to the facing sides of both films. Alternatively, the barriermaterial could take the faun of a separate material (or third film)simply positioned between the first and second films.

Turning now to the steps of the method of FIG. 1, first and second filmsmay be identical or different materials provided that they are each madefrom a material that may be adhered together to form a fluid-tight seal.Films can be formed from a variety of polymers such as thermoplasticresins, other elastomeric materials, thermoset materials, and compositesthereof, including but not limited to, thermoplastic polyurethane (TPU),ethylenevinylacetate/polyethylene copolymer, polyester elastomer (e.g.Hytrel® material available from DuPont), polyethylene, polypropylene,neoprene, natural rubber, dacron/polyester, polyvinylchloride,thermoplastic rubbers, nitrile rubber, butyl rubber, sulfide rubber,methyl rubber, silicone rubber, polyvinyl acetate, Buna-N, Buna-S,polystyrene, ethylene propylene, polybutadiene, chlorfulfonatedpolythylene, nylon, partially set thermoset materials, ethylene vinylacetate (EVA) foam, thermoset rubber, prepreg and others. One particularexample of a suitable class of TPU film for the method of the presentinvention is a polyester urethane film available from JP Stevens underproduct no ST1880. This film class has a Shore A hardness of 88-92 and aformulation having a base resin of Pellethane® (available from DowChemical), Estane® (available from Noveon) or Elastollan® (availablefrom BASF). One skilled in the art can appreciate that any number ofthermoplastic, elastomeric, and thermoset materials are suitable for usein the present invention, provided such materials are flexible andcapable of forming a fluid-tight seal with another material having thesame characteristics. It is further envisioned that sheet films employedin the food packaging arts, and other materials such as polyester orbiaxially-oriented polyethylene terephthalate (e.g., Mylar® film), couldtake advantage of the manufacturing method of the present invention.

Moreover, while the method of FIG. 1 has been described as providing afirst and second “film”, such film need not be a single ply of material.Indeed, either or both of the first and second films may be a laminateof a thermoplastic layer and a substrate applied to only one side of thepolymer layer (permitting the opposite side of the polymer layer to besealed to the second film (or laminate)). Substrates may be any of avariety of textiles, for example, any synthetic or natural fiber orfabric. One non-limiting example of a fabric used as a laminate of aninflatable bladder for footwear is a non-woven, high-density 70% nylonand 30% polyester blend, available from Dae Woo InternationalCorporation (Pusan, Korea). Several methods have been developed to formlaminates between polymer layers and substrates. One such methodincludes direct cast extrusion of a thermoplastic resin onto a substrateto form a thin layer thereon. Provided that the substrate is at leastpartially porous, the polymer resin will penetrate the pores of thesubstrate and bond thereto. Other laminate forming methods known tothose skilled in the art would also be suitable for forming a laminatefor use as the films of the present invention. For example, a laminatemay be formed from a polymer layer and a substrate by adhering thepolymer layer to the substrate by application of heat and pressure, anadhesive or bonding agent, or by ultrasonic bonding. Further, thelaminate may include more than one polymer layer, as well as more thanone layer of substrate, provided that at least one polymer layer is ableto be sealed to another polymer layer, to form at least one compartmentof the inflatable bladder.

Turning now to Step 1(b) of the method set forth in FIG. 1, a barriermaterial is applied to a first side of the first film. The barriermaterial may be any material or treatment that prevents the first filmfrom adhering to the second film of the invention upon application ofheat and/or pressure. More particularly, the barrier material may be apaint, ink, polytetrafluoroethylene (PTFE) (e.g., TEFLON®) coating,silicone coating, paper, textile, photosensitive agent, foil, wire,particulate or surface treatment that maintains the integrity of thefirst and second films, but still prevents the films from adhering toeach other where the barrier material or treatment has been applied.

Where the barrier material is a paint, for example, the paint could beapplied to the first film in accordance with Step 1(b) of the method ina manner similar to silk-screening. Silk-screening (or screen printing)is a long-used process for economically mass producing signage, printsand fabric designs, etc. The basic idea in silk-screening (as generallyshown in FIG. 11) is to create a master screen through which paint (orother suitable media) passes to impart a design or imprint on a largenumber of duplicates. Generally, a drawing or tracing of a design istransferred by means of a photo process to a thin, fine grain photosensitive gel coated cloth (or “silk”), which is tightly stretched overa frame. When the gel is exposed, the part of the gel that is exposed tolight hardens or cures, while the unexposed part remains soft. Aftercuring, the soft gel is washed away, leaving a “negative” image of thedesign on the silk. The silk is open-celled (like a screen), so that thepaint or other media can pass therethrough.

The framed silk is placed against the object upon which the design is tobe imparted. Paint is then applied thereto and pulled across the silkwith a squeegee or similar device to transfer the design through thesilk to the object below. Where a design having multiple colors isdesired, a separate screen must be prepared for each color (similar tothe color separation process in conventional ink-printing methods). Withthe silk-screening method, thousands of “prints” can be made from asingle silk. More recently, the printing screens are formed frommonofilament materials such as polyester, rather than silk.

By applying the silk-screening technique described above to the methodof the present invention, a variety of bladder configurations and sizescan be “printed” on or imparted to the first film of Step 1(a) tofunction as the barrier material of the present invention. For example,FIG. 2 illustrates a negative image of an inflatable bladder design orconfiguration 20 as formed on a printing silk or screen 24. Where thescreen or silk is visible in area 22 is where the paint, ink of othermedia will be transferred through the screen and onto the first film ofStep 1(a). Bladder design or configuration 20 comprises a circularelement 26 and linear elements 28, which prevent transfer of the paint,ink or other media onto the first film. When the first and second filmsare adhered together (in Step 1(d) of the method discussed below), thefirst and second films will adhere to each other at circular element 26and linear elements 28 to form the equivalent of the circular welds andweld lines of the prior art described above, to control the thicknessand inflation of the bladder and, with respect to apparel or footwear,to accommodate the anatomy of the human body. Negative image 20 of theinflatable bladder design or configuration also includes a visible areaof screen 30, which extends from the edge of the screen into area 22.Area 30 is conduit-like in shape and is intended to form a passage forreceiving an inlet or outlet valve or other fitting to permit fluid tobe introduced into and/or released from the inflatable article orbladder of the invention. While area 30 is shown as being conduit-shapedin FIG. 2, it should be understood by those in the art that area 30 maytake any shape necessary to accommodate the fittings needed to inflateor deflate the inflatable article of manufacture or bladder.

It should also be realized by those skilled in the relevant art thatwhile a particular negative bladder design or configuration has beenillustrated in FIG. 2, the negative design of the bladder (and thus, thebladder ultimately formed by the method of the present invention) maytake any shape required for the intended purpose or function of theinflatable article or bladder. For example, when used in footwear, thebladder may be configured to fit within the tongue of the shoe, alongthe medial and lateral sides, around the ankles and under the arch, heelor metatarsal heads. Similarly, the bladder may be designed to fitwithin the shell of a life preserver, chest protector, helmet, gloves,air mattress, packaging, or any other inflatable article of manufacture.

Likewise, the described linear and circular elements may be placed inany position to accommodate the function of the bladder and to controlinflation and/or bulging of the bladder, as necessary. In addition, thelinear and/or circular elements need not be linear or circular, but maybe elongated, curved or of any geometry to meet the functionalobjectives of the bladder or the anatomy of the user, where the bladderis to be incorporated into an article of manufacture to be worn by ahuman.

Continuing with the steps of the method of FIG. 1, after creating ascreen 24 with a negative image of the desired inflatable bladder designor configuration 20, screen 24 is placed on top of a first side 40 offirst film 42, as shown in FIG. 3. A paint, ink or other media P is thenapplied to and pulled across screen 24 to transfer the configuration ordesign of the inflatable bladder onto first side 40 of first film 42, asvisible area 22. Thus, by transferring the image of the inflatablebladder configuration onto the first side of the first film with paint,ink or other media, a barrier material is applied to the first side ofthe first film as required by Step 1(b) of the method of the presentinvention.

FIG. 4 illustrates Step 1(c) of the method of FIG. 1. In this step, afirst side 44 of a second film 46 is positioned over first side 40 offirst film 42, such that the barrier material image 48 of the inflatablebladder configuration 20 and the barrier material image 50 of theconduit 30 is positioned between first film 42 and second film 46. InFIG. 4, the barrier material is visible through second film 46.

In Step 1(d) of the method of FIG. 1, first film 42 is adhered to secondfilm 46 so that the films are sealed together to form a sealedperipheral area except where the barrier material has been applied tothe first film, to form at least one inflatable compartment. Where thebarrier material, has been applied to the first film, no adherence willoccur to create the inflatable compartment of the resulting inflatablearticle or bladder. In FIG. 4, the sealed area is shown in hatched area49, while the at least one inflatable compartment is shown at 52. Uponsealing, circular element 26 and linear elements 28 form circular andlinear seals or welds 54, 56.

The first and second films may be adhered by a heated platten broughtinto contact with the films, or the coextensive films could be fedtogether through heated rollers commonly known in the laminating art,for example. Other known means for sealing or laminating thermoplasticfilms (e.g., ultrasonic welding) could also be employed to achieve theobjects of the present invention. The films could also be madephotosensitive so that they would adhere to one another upon applicationof light.

In Step 1(e) of the method of FIG. 1, and as shown in FIG. 5, a cut ismade along the edge of the sealed peripheral area near the inflatablecompartment at cut line 58 to form an inflatable article or bladder 60having at least one inflatable compartment 52, a circular weld 54,linear welds 56, a deflation/inflation conduit 50 and a peripheral edge62 (see FIG. 6). This cut can be made by a cutting die configured inaccordance with the pre-defined or customized bladder configuration (butslightly large) or by other suitable cutting means such as lasercutting, or water jet cutting.

Inflatable bladder 60 of FIG. 6 may be secured to or within an articleof manufacture, for example, an article of footwear, by securing thebladder to the shoe components along peripheral edge 62 by stitching, anadhesive or other suitable fastening means.

Thus, as described above, this embodiment of the method of the presentinvention enables an inflatable article or bladder for an inflatablearticle, to be manufactured quickly, easily and without the use ofexpensive article or bladder configuration-specific, metal tooling.Indeed, the method can be utilized with known silk-screening or printingand laminating techniques to allow for the continuous manufacture ofmultiple-shaped inflatable articles or bladders at relatively low cost.Moreover, and most advantageously, when a bladder configuration changeis required, there is no need to order, machine and replace an expensivepiece of metal tooling in the manufacturing process. Instead, a newscreen/negative image of the newly desired bladder configuration is madeand exchanged for the prior screen/negative image—a simple, quick andinexpensive process, which is also compatible with the down-stream stepsof the manufacturing process (i.e., adhering and cutting).Alternatively, a new screen/negative image could be digitally fed to themanufacturing process.

Returning to a discussion of Step 1(b) of the method of FIG. 1, thesilk-screening technique described above is particularly advantageousfor the manufacture of inflatable articles or bladders for consumerproducts in that silk-screening allows for the use of multiple colors tocreate bladders having visually appealing, colored designs or cosmetics.It is also envisioned that multiple colors could be used withappropriately designed screens to transfer an image of a producttrademark, brand or logo onto the films and, thus, the inflatablearticle or bladder.

While the barrier material and application step of the present inventionhas been described above with respect to paint or ink as used with asilk-screening or printing technique, it is envisioned that the barriermaterial may take other forms. For example, the barrier material may bea paper (e.g., adhesive-backed paper), fabric, foil, wire, particulate,or plastic material (such as polyethylene) applied to the first side ofthe first film to prevent the first and second films from adheringtogether to form at least one inflatable chamber.

It is also possible that the barrier material may be “free-floating” andnot attached to either the first or second film. Indeed, the barriermaterial could be a particular type of film (or films) positionedbetween the first and second, films that would not bond to the first andsecond films (e.g., the film would release from the first and secondfilms as they cool, following the application of heat). Other“free-floating” barrier materials can include, for example, paper,fabric, foil, wire, particulate, or plastic material positioned betweenthe first and second films. Alternatively, the barrier material may betemporarily applied to one of the first or second films.

In another embodiment, the barrier material could be a particulate,soap, surfactant, release coating or agent, or a polytetrafluoroethyleneor silicone coating, sprayed over an appropriately shaped stencil totransfer the barrier material, in the desired article or bladderconfiguration, onto a first side of the first film to prevent the firstand second, films from adhering to each other during the sealing step ofthe invention.

In yet another embodiment of the invention, and utilizing thesilk-screening or printing technique described above, the barriermaterial could also be an acid or other liquid chemical, which istransferred to a first side of the first film to chemically etch,corrode or abrade the first film, to inhibit attachment of the firstfilm to the second. It is also envisioned that a photosensitive materialcould be transferred to the first film and subsequently exposed to lightto meet the objectives of the barrier material of the invention.

In still another embodiment, the first film could be calendared betweena hot roller and another hot or cold roller to apply or emboss a texture(having the overall desired bladder configuration) on one side of thefirst film to prevent it from adhering to the second film to form aninflatable compartment.

It is also envisioned that the method of present invention is capable ofapplying printing techniques (that is, printing films and rollers) usedby the newspaper or printing industry to transfer a variety ofinflatable article or bladder shapes onto a first film for adhering to asecond film to form an inflatable compartment.

In another aspect of the invention, and with reference to FIG. 7, theabove-described embodiments of the invention can be utilized inconjunction with “on-demand” printing technology to create customizedinflatable products. Specifically, Step 1(b) of applying a barriermaterial to the first film could be accomplished by printing the barriermaterial on the film (possibly using the techniques described above)with a “smart” digital printer 70, which has access to a database 72 ofcustomized information to create unique designs having customizedbladder configurations, customized placement of circular and linearelements, and customized colors.

In practice, a customer for a shoe, for example, might enter into acomputer 74 a specific color or design that the customer wants to appearon the shoe. The design could be indicia such as a name, words, orsymbols or could be a photograph of a person or place. It is alsoenvisioned that an anatomical scan of the customer's foot could beentered (e.g., at a point-of-purchase kiosk or display) in order toenable customized manufacture of an inflatable article or bladder, whichaccommodates the anatomy of the customer's foot to enhance fit,cushioning and support. The entered information would then betransmitted to database 72 to which printer 70 has access. The printerwould then access the database and print the unique design on a firstfilm 76. First film 76 could be configured as a rolled sheet material,which is then joined with a similarly rolled second film 78. First film76 and second film 78 would then be calendared through heated rollers77, 79 to adhere the films together and create the inflatablecompartment of the bladder. The bladder would then be cut from the filmsusing the methods described above. Where the bladder is cut from thefilms using a laser, the laser could also be made “smart” by connectingthe laser to the database to control cutting of the bladder from thefilms, in accordance with the customized bladder design printed on thefilm. The present invention also contemplates that the bladder could be“cut” from the films by providing a cutting die with a chemical thatcorrodes, dissolves or “eats” through the films.

This method of the present invention is not only customizable, but iscontinuous in nature, in that there is no need to interrupt the steps ofthe method to change-out for bladder designs of differingconfigurations, colors or indicia. When the bladder is built into ashoe, the bladder may form an exoskeleton of the shoe as described inU.S. Pat. No. 5,343,638. Because the bladder has a design printed on theinside of the film, the design may be made visible on the outside of theshoe to form a unique customized shoe.

Similarly, the barrier material could take the form of a thermallyreflective material to provide the bladder with insulating properties.The bladder could then be constructed into apparel, for example, to forman insulating shirt, jacket, vest, pant, or other article of apparel.

It is further envisioned that the barrier material could be a printedbackground design (for example, an underwater scene), and that thebladder could be filed with a fluid and ornamental elements (forexample, plastic fish and sparkles), for use in children's wear or otherarticles of manufacture directed to a specific type of consumer.

It is also contemplated that the bladder could, be formed from more thantwo films, to create a bladder having multiple layered inflatablecompartments. In this embodiment, specific barrier materials and filmscould be selected so that each layered, inflatable compartment of thebladder has a different inflation quality or characteristic to addressthe objectives of the inflatable article of manufacture.

As noted above, the inflatable bladder formed by the method of thepresent invention also comprises a conduit 50 for coupling with aninflation valve or a deflation valve. While this conduit serves as onemeans or structure for joining inflation and deflation fitments to theinflatable article or bladder per se, it is also envisioned thatfitments known in the fluid transfer and control art could be attachedto the article via an opening pre-formed in the second film prior toStep 1(c) of the method of FIG. 1. It is also envisioned that materialsknown in the art for constructing one-way valves and other structureuseful in the art of inflatable technology could be inserted between thefirst and second films to permit and control the ingress and egress offluid from the inflatable compartment.

FIGS. 8A and 8B illustrate how a conventional fitment may be constructedinto bladder 60 during the manufacturing process of the presentinvention. FIG. 8A shows the manufacturing process of the method of FIG.1 after completion of Step 1(c), but before Step 1(d). As shown in FIG.8A, a barrier material 80 is positioned between a first film 82 and asecond film 84. First film 82 and second film 84 are both provided withan opening 86,88 suitably positioned for placement of a pump, inletvalve, release valve, or other known fitment for an inflatable bladder.A washer 90 constructed of a film material having properties similar oridentical to second film 84 is positioned over opening 88. A fitment,for example, a digitally operated pump 92 constructed of a materialhaving properties similar or identical to first film 82, is positionedover opening 86. Step 4 of the present invention is then performed toadhere first film 82 to second film 84 in all areas except where barriermaterial 80 has been applied to second film 84. Washer 90 can then beadhered to second film 84 and pump 92 to first film 82. Elements 82 and84, 90 and 84, and 92 and 82 are adhered to one another in the areasnoted by dashed lines (where barrier material 80 is absent). After thesesteps, and as shown in FIG. 8B, the pump is adhered to the first filmand the washer is adhered to the second film in an area of the bladderwhere an inflatable compartment fluid conduit has been formed. Thus,fluid (illustrated by arrow F) is brought into the bladder, via thepump, to inflate the inflatable chamber defined by the area ofapplication of the barrier material.

While a pump for bringing fluid into the bladder has been illustrated inFIGS. 8A and 8B, it should be noted that other fitments (for example,fluid release valves, fluid inlets, fluid regulators and check valves)may be attached to the films using the same technique. Further, itshould be understood by those skilled in the art that other knowntechniques for securing fitments to inflatable bladders may be used withthe method of the present invention.

FIG. 9 illustrates another method for manufacturing an inflatablearticle of manufacture, for example, an inflatable article of footwear.In one embodiment, the method generally comprises the steps of 9(a)providing a first film, 9(b) applying a release coating to a firstsurface of the first film in a pattern corresponding to theconfiguration of an inflatable compartment of an bladder, 9(c) curingthe release coating to the first surface of the first film, 9(d)providing a second film with the first film to form a layered elementsuch that the cured release coating, is disposed between the first filmand the second film, 9(e) positioning the layered element between afirst ply of material and a second ply of material, 9(f) applying heatand pressure to the first and second plies of material to adhere thefirst film to the second film except in the area where the releasecoating has been applied to the first film, to form an inflatablecompartment surrounded by a sealed perimeter, 9(g) removing the firstand second plies of material from the adhered first and second films,9(h) cutting along the sealed perimeter to form an inflatable bladderhaving an inflatable compartment and a sealed attachment margin, and9(i) incorporating the inflatable bladder into an article of manufactureby attaching the inflatable bladder to the article of manufacture at theattachment margin.

Turning now to a more detailed discussion of the method according to oneembodiment, as shown in FIG. 9, a first film is provided in first step9(a) of the method. The first film may be sized to accommodate thebladder or bladders to be manufactured therefrom and may be provided inindividual sheet or roll form. First film may be a low densitypolyethylene film. In one particular embodiment, the first film is about0.085 inch thick low density polyethylene film and is sold under productno. MC100V by Bloomer Plastics, Inc. (Bloomer, Wis.). In addition tothis film, the films and materials identified in paragraph [0037] ofthis disclosure are suitable for the first film of the method of FIG. 9.Moreover, one skilled in the art will appreciate that any number ofpolymer materials are suitable for use in the method of FIG. 9, providedsuch materials are flexible and capable of forming a fluid-tight sealwith another material having the same physical properties. Naturally,the characteristics of the film may also be modified as a function ofthe fluid to be used in the bladder. If, for example, the bladder isintended to be used to contain a liquid or a large molecular-weight gas,the bladder may allow diffusion or reverse diffusion into and out of thebag without diverging from the spirit of the, invention. Similarly, thebladder may be purposefully made porous to allow fluid to diffuse orescape from the bladder when a predetermined internal pressure isreached. This may be done by adding perforations to the film or by usingfilms with known diffusion rates.

As shown in FIG. 10, first film 1000 has a length, width and thickness,which defines a first or inner surface 1010 and a second or outersurface 1020. In accordance with step 9(b) of the method of FIG. 9, arelease coating 1030 is applied to first surface 1010 of first film 1000in a pattern corresponding to the configuration of an inflatablecompartment of a bladder. Like the barrier material of the method ofFIG. 1 (for which “release coating” and “release agent” areinterchangeable terms), release coating 1030 prevents first film 1000from adhering to the second film of the method to form an inflatablecompartment (to be described in more detail below). The release coatingof the method of FIG. 9 is preferably a silicone-fortified coating thatis curable by ultra-violet light to affix the release coating to firstsurface 1010 of first film 1000. One such silicone-fortified releasecoating is 08D003D UV, available from Craig Adhesives & Coatings(Newark, N.J.). Obviously, other materials are suitable for use as therelease coating of the method of FIG. 9 (including those discussed inparagraphs [0039], [0055] and others herein), so long as such materialscan be appropriately applied and affixed to the first film to preventthe first film from adhering to the second film upon the application ofheat and pressure (or other bonding techniques to be discussed in moredetail below).

Release coating 1030 may be applied to first film 1000 using anysuitable technique, including those discussed above in connection withthe method of FIG. 1. In a preferred embodiment, release coating 1030 isapplied to first surface 1010 of first film 1000 by screen printing.Akin to the screen-printing technique described herein in connectionwith the method of FIG. 1, a negative image of an inflatable bladderpattern is formed on a screen. With reference to FIG. 11, screen 1110 ispositioned above first surface 1010 of first film 1000 on a screenprinting unit identified generally as 1120. Release coating 1030 ispulled across screen 1110 by a transfer arm or squeegee 1125 to transferthe pattern corresponding to the inflatable compartments of theinflatable bladder to first surface 1010. It should be noted by thoseskilled in the art that any screen printing process or machine may beused to accomplish applying step 9(b) of the method.

The inflatable bladder pattern shown in FIG. 10 (which is transferred tofirst surface 1010 of first film 1000 in FIG. 11) corresponds to abladder for use in the upper of an article of footwear, and comprises aninflatable instep or tongue compartment 1040 and two inflatable lateralcompartments 1050. Inflatable compartments 1040, 1050 are formed in theareas where release coating 1030 passes through screen 1110 to firstsurface 1010 of first film 1000. The pattern of FIG. 10 furthercomprises circular area 1060 and generally linear areas 1070. Theseareas are formed where the release coating does not pass through thescreen to the first film and are, thus, non-inflatable. Circular andlinear areas 1060, 1070 are provided to control the thickness andinflation of the bladder, and with respect to footwear in particular, toaccommodate the anatomy and bone structure of the foot to avoiduncomfortable pressure points.

A perimeter 1080 extends about the periphery of the bladder pattern.Perimeter 1080 is also devoid of release coating 1030, so that the firstand second films are able to adhere to each other during the adheringstep of the method of FIG. 9. This adhered perimeter ultimately forms anattachment margin that facilitates incorporation of the inflatablebladder into the article of footwear or other article of manufacture, tobe discussed in more detail below.

It should be realized by those skilled in the art that while aninflatable tongue bladder is shown in FIG. 10, the inflatable bladder ofthe method may take any configuration in keeping with its intendedpurpose or function. For example, for footwear, the inflatable bladdermay be configured to fit within the tongue, along the medial and/orlateral sides, around the ankle, or under the arch. Similarly, theinflatable bladder may be designed to fit within the shell of a lifepreserver, jacket, chest protector, or helmet, or within a glove or anyother inflatable article of manufacture. Moreover, the describedcircular and linear areas (which could, of course, take any shape orgeometry) may be placed in any position to meet the functionalobjectives of the bladder and to control inflation of the bladder, asnecessary.

Continuing with the steps of the method of FIG. 9, following applicationof a release coating to the first surface of the first film, the releasecoating is cured to the first film by exposing the first film with theapplied release coating to a source of ultra violet (UV) light (see Step9(c)). For example, silicone-fortified release coating 08D003D UV iscured to the first film by application of UV light until cured.Obviously, the requirements for curing the release coating are dependenton the type of release coating and the size of the area to beilluminated. After curing, the release coating is fixed to the firstsurface of the first film and will not substantially melt, flake, orotherwise degrade upon the application of heat, pressure, ultrasonicenergy or the application of other forces, energy or laminating/bondingtechniques.

It will be realized by those skilled in the art that the release coatingcan be cured in accordance with known curing techniques (for example,with a hand-held UV light or a UV light tunnel), so long as the curingtechnique is appropriate to the formulation and properties of theapplied release coating and the remaining steps of the method.

Turning now to FIG. 12, and in accordance with Step 9(d) of the methodof FIG. 9, a second film 1200 having a first or inner surface 1210 and asecond or outer surface 1220 is provided with first film 1000 to form alayered element 1230. More particularly, layered element 1230 is formedby placing first surface 1210 of second film 1200 in facing relationshipwith cured release coating 1030, such that the release coating issandwiched or disposed between first surface 1010 of first film 1000 andfirst surface 1210 of second film 1200. Second film 1200 is formed fromthe same low density polyethylene film as first film 1000, so that thefirst and second films are capable of bonding to each other in the latersteps of the method of FIG. 9. As noted above with respect to first film1000, second film 1200 may be formed from any type of thermoplastic orelastomeric film. However, the first and second films should be formedfrom the same material, similar materials, or compatible materials toallow for the required bonding or sealing between the two films.

In accordance with Step 9(e) of the method of FIG. 9, and with referenceto FIG. 13, layered element 1230 (i.e., first film 1000 with curedrelease coating 1030 and second film 1200) is positioned or sandwichedbetween a first ply of material 1300 and a second ply of material 1310.First and second plies 1300, 1310 are generally not affixed to layeredelement 1230, but instead layered element 1230 is generally looselypositioned between first and second plies 1300, 1310. First and secondplies 1300, 1310 can include at least one textured surface. For example,plies can include a woven surface, a grooved surface, a nubbed surface,a wavy surface, or a combination thereof. In preferred embodiments, atleast one of the plies is sufficiently textured to prevent or reduce theentrapment of air near the outer surface of layered element 1230 duringthe step of adhering first film 1000 to second film 1200. In otherembodiments, at least one of the plies is sufficiently textured toprevent or reduce the movement of layered element 1230 during the stepof adhering first film 1000 to second film 1200. In some embodiments,the plies can include glass or carbon fibers, fabric, silicon, paper,polyethylene terephthalate (such as biaxially-oriented polyethyleneterephthalate), or nylon. For example, the plies can include siliconcoated paper, textured silicon sheet, polytetrafluoroethylene sheet,textured biaxially-oriented polyethylene terephthalate, orpolytetrafluoroethylene-treated, fiberglass cloth. The plies arepreferably resistant to temperatures that are used for adhering firstfilm 1000 to second film 1200. In some embodiments, the plies resiststicking to first film 1000 or second film 1200 during the step ofadhering the first and second films together. In some embodiments, theplies are made of a stick-resistant material (e.g.,polytetrafluoroethylene). In other embodiments, plies are treated with astick-resistant material (e.g., polytetrafluoroethylene).

The plies can perform several functions: (1) they can carry the layeredelement, comprised of the first and second films and release coating,through a laminating process to prevent the layered element fromadhering or melting to the heated elements of the laminating apparatus;(2) the woven texture of the cloth can prevent air from being trapped onthe first and/or second films (e.g., trapped on one or more surfaces ofthe films) or can reduce the amount of air being trapped on the firstand/or second films, which could cause bubbling, warping, inconsistentlamination between the films, or weak or thin areas in the bladder; (3)the plies can prevent or reduce any unintended pre-heating of thelayered element when in the proximity of heated elements of thelaminating process (for example, when the layered element is proximate,but not yet inserted into the nip rolls of a rotary lamination machine)and/or (4) the plies can prevent or reduce shifting or movement of thecomponents of the layered element relative to each other.

Examples of polytetrafluoroethylene/fiberglass reinforced material fromwhich first and second plies 1300, 1310 can be made are available fromPrecision Coating Co., Inc. (Dedham, Mass.), under product nos. PC-10,PC-14, PC-10 TR, PC-10 Porous, PC-14 Porous, 100-8SW2, and 100-10sw. Oneexample of a silicon/fiberglass reinforced material from which first andsecond plies 1300, 1310 can be made is available from Precision CoatingCo., Inc., under product no. PC S/W 10. In some embodiments, thematerial from which first and second plies 1300, 1310 is made has athickness of about 5 to about 20 mil (about 0.127 mm to about 0.508 mm)such as about 10 to about 15 mil (about 0.254 mm to about 0.381 mm).Plies 1300, 1310 can be cut or sized to accommodate the dimensions ofthe layered element sandwiched thereinbetween. While various types ofsuitable plies have been described, it should be realized by thoseskilled in the art, that any material which is capable of performing theprimary functions above would be suitable for plies 1300, 1310.

Moving on to Step 9(f) of the method of FIG. 9, heat and pressure areapplied to first and second plies 1300, 1310 (with layered element 1230positioned thereinbetween) to adhere first film 1000 to second film1200, except in the area or vicinity where release coating 1030 has beenapplied to first film 1000 to form an inflatable compartment surroundedby a sealed perimeter. For example, in one embodiment, the first filmmay be adhered to the second film except where the release coating ispresent and in the area immediately adjacent to where the releasecoating is present. In a preferred embodiment of the invention, the heatand pressure applying step of the method is accomplished using a heateddrum rotary lamination machine. Using a heated drum rotary laminationmachine, heated fluid (e.g., oil) from an auxiliary source can becirculated through a rotary dram of the machine, which in turn radiatesand applies heat to the films brought near the rotary drum. A heateddrum rotary lamination machine is desirable, as the heated fluidcirculated through the drum provides an even temperature across thesurface of the drum, to provide for consistent melting and, thus,high-integrity bonding or lamination of the films.

A rotary lamination machine 1400 is shown in FIG. 14. Rotary laminationmachine 1400 comprises, among other things, a stand-off feed tray 1410,a heated rotary drum 1420, a nip roll 1430, a conveyor belt 1440, and aspring-loaded exit tray 1450. To utilize rotary lamination machine 1400to perform the adhering step (Step 9(f)) of the method of FIG. 9, firstand second plies 1300, 1310 with layered element 1230 positionedthereinbetween are brought to the machine and placed on stand-off feedtray 1410 to reduce unintended pre-heating of the combined plies andlayered element. The plies are then fed into the machine by nipping orpinching them between nip roll 1430 and heated rotary drum 1420 in thedirection of arrow 1 shown in FIG. 14. The plies are then carriedagainst and around the heated rotary drum via conveyor belt 1440 (arrow2). Like plies 1300, 1310, conveyor belt 1440 can be formed from amaterial similar to that described for use in plies 1300, 1310 tofacilitate movement of the plies around the heated rotary drum and toprevent the first and second films from sticking or adhering to the beltcluing the laminating process. In one embodiment, conveyor belt 1440 canbe formed from such a material and layered element 1230 is placeddirectly on conveyor belt 1440 without using one or both of plies 1300,1310. For example, the conveyor belt can be made ofpolytetrafluoroethylene/fiberglass material to facilitate movement ofthe layered element 1230 around the heated rotary drum and to preventthe first and second films from sticking or adhering to the belt duringthe laminating process.

To bond or adhere first and second films 1000, 1200, rotary drum 1420 ofmachine 1400 is heated to operate at a temperature and set to run at aspeed that is dependent upon the selection of films 1000, 1200, barriermaterial 80 (e.g., release coating 1030), and plies 1300, 1310, butwhich temperature and speed are selected to be sufficient to melt atleast one of the films at least partially and in some embodiments, tocompletely melt at least one or both of the films, and to ensure propermelting and bonding of the films 1000, 1200. As plies 1300, 1310 arecarried about the heated rotary drum (and pressure is applied to theplies and layered element by the drum and conveyor belt), first andsecond films 1000, 1200 melt and bond or adhere to each other except inthe area where release coating 1030 has been applied to first film 1000.Conveyor belt 1440 carries plies 1300, 1310 with layered elementthereinbetween to the lowermost tangential point of the heated rotarydrum (arrows 3 and 4), where it then conveys the plies away from thedram and toward a spring loaded tray 1450 (arrow 5) that allows forremoval of the plies and the now-adhered first and second films disposedthereinbetween from the rotary lamination machine (arrow 6).

While the adhering step has been described in connection with a heatedrotary lamination machine, it should be understood by those skilled inthe art that other laminating techniques can be utilized to accomplishthe objectives of the methods described herein, including, but notlimited to, use of a pressure source and a heat source. Examples ofsuitable pressure sources include presses (e.g., a hydraulic mess) andapplication of vacuum (e.g., via vacuum bag or vacuum table). Examplesof suitable heat sources include heated plates; heat lamps (e.g.,infrared lamps); conventional, convection, or microwave ovens; andresistance heaters, among others.

In one embodiment, an ultrasonic bonding horn is used to perform theadhering step. The use of an ultrasonic bonding horn can includeultrasonic rotary/continuous bonding horn techniques such as those whichinclude assembling two or more layers of materials by passing thembetween a vibrating horn and a rotary drum wherein high frequencymechanical motion of a vibrating horn and compressive force between thehorn and a rotary drum create frictional heat at the point where thehorn contacts the material(s).

In another embodiment, the adhering step can include application ofvacuum. Application of vacuum can prevent air from being trapped on thefirst and/or second films (e.g., trapped on one or more surfaces of thefilms) or can reduce the amount of air being trapped on the first and/orsecond films during the adhering step and can prevent or reduce shiftingor movement of the components of the layered element relative to eachother during the adhering step.

For example, films 1000, 1200 can be placed between plies 1300, 1310 andthe resulting layered element 1230 can be subjected to vacuum and heatand/or additional pressure. In one embodiment, layered element 1230 isplaced into a vacuum bag and vacuum is drawn on the bag. Heat and/oradditional pressure (e.g., via a press) can then be applied to thevacuum bag and layered element 1230 causing first and second films 1000,1200 to melt and bond or adhere to each other except in the area whererelease coating 1030 has been applied to first film 1000. In anotherembodiment, layered element 1230 can be placed on a vacuum table,covered with a sheet or film, vacuum drawn on the layered element 1230,and heat and/or additional pressure (e.g., via a press) can then beapplied to the layered element.

Obviously, other laminating techniques and devices known in the art forbonding or laminating thermoplastic or elastomeric films and materialswould be suitable for achieving the objectives of the present invention.

Following removal of the plies and now-adhered first and second filmsfrom the rotary lamination machine, the plies and films are cooled.After cooling, plies 1300, 1310 are removed from the layered element bypeeling ply 1300 from second film 1200 and ply 1310 from first film 1000(Step 9(g) of the method). Plies 1300, 1310 can be conveniently andefficiently reused for the additional lamination of films. As statedpreviously, plies 1300, 1310, particularly textured plies,advantageously can prevent or reduce (a) air being trapped on the firstand/or second films, and (b) shifting or movement of the components ofthe layered element relative to each other, both of which could resultin an inconsistent bond or a bond of compromised integrity. With thislamination technique the resulting adhered films are substantially flatacross the surfaces thereof (that is, there are no raised weld lines,seams, ridges or bulges). This facilitates manipulation of the film forassembly of the inflatable bladder into the article of footwear or otherarticle of manufacture.

It should also be noted that following the melting and lamination offilms 1000, 1200, any textured surface (or warp and weave) of plies1300, 1310 can be imparted to second or outer surface 1020 of first film1000 and second or outer surface 1220 of second film 1200. Thistexturing of films 1000, 1200 (partially represented as texture T inFIG. 15) can improve handling and attachment of the inflatable bladderinto an article of footwear (or to the structure thereof), particularly,if such attachment is by means of a liquid adhesive, as the adhesive isable to flow into the recesses of the textured surface to improve thebond.

As stated above, first film 1000 is adhered to second film 1200 exceptin the area where the barrier material has been applied to form aninflatable compartment surrounded by a fully sealed perimeter. FIG. 15is a top plan view of adhered first and second films 1500 adheredtogether except in the area where the barrier material, e.g., releasecoating 1030, has been applied to form an inflatable compartment 1510surrounded by a sealed perimeter 1520 and sealed attachment margin 1550.Unlike conventional radio frequency (RF) welding that forms weld linesor seams only in the vicinity where RF energy has been applied to afilm, perimeter 1520 (formed by adhered films 1000, 1200) is adheredfrom the edge of the inflatable compartment (i.e., the edge of thebarrier material) across the entire surface thereof to the edges of theadhered films, as shown by arrows S in FIG. 15.

Turning now to Step 9(h) of the method of FIG. 9, and with continuingreference to FIG. 15, an inflatable bladder can be cut from thenow-adhered films by cutting the sealed perimeter of the films along acut line C to form an inflatable bladder 1540 with a sealed attachmentmargin 1550. Inflatable bladder 1540 can be cut from the adhered filmsusing any suitable means, including any of the cutting means previouslydiscussed in this disclosure.

Finishing with Step 9(i) of the method shown in FIG. 9, the inflatablebladder is incorporated into an article of footwear or other article ofmanufacture by attaching inflatable bladder 1540 to the article offootwear at attachment margin 1550. The inflatable bladder of the methodof FIG. 9, with the fully sealed attachment margin 1550. is particularlywell suited for incorporation into articles of manufacture (including,but not limited to, footwear), because it can be textured (for improvedhandling), is substantially flat along its surface, and has anattachment margin comprised of sealed films for improved attachment tothe article of manufacture. More specifically, RF welded bladders can bedifficult to assemble into footwear, for example, because the weld linescan cause the films of the bladder to curl or buckle along the weldlines. This curling can interfere with placement and attachment of thebladder to the article of footwear. In addition, with RF welding, thefilms are attached only at the weld lines, which leaves the filmsseparate from each other along the exterior edge of the inflatablebladder (i.e., at the attachment margin). Because the films of theinflatable bladder are not adhered, special care must be taken to ensure(1) that a stitch line goes through both films of the attachment margin(if adhered to the article of footwear by stitching), (2) that anadhesive is applied to both films (if adhered to the article of footwearby adhesive) to ensure that the inflatable bladder is adequatelyattached to the article of footwear and is capable of withstanding theforces and increased pressure that will be applied to the inflatablebladder at the margin, or (3) that at least a portion of the unadheredportion of the films is cut away. The substantially flat and adheredfilms of attachment margin 1550 formed by the method of FIG. 9 providefor easy and effective attachment of the inflatable bladder to thearticle of footwear (or other article of manufacture).

Having described the fundamental steps of the method of FIG. 9 of thepresent invention, attention will now be given to other or optionalsteps. The inflatable bladder of the present invention can bepermanently inflated (i.e., air is permanently sealed in the inflatablecompartment of the bladder) or inflation of the inflatable bladder canbe customized by the user by attaching an inflation device and adeflation device to the inflatable compartment of the bladder. The stepsfor attaching one type of inflation and deflation device will now bedescribed with respect to the inflatable bladder formed by the method ofFIG. 9. FIG. 16 shows a valve body 1600 having an open-ended plungerhousing 1610, an open-ended pump connector 1620, and an open-endedsealing collar 1630. Plunger housing 1610, connector 1620 and sealingcollar 1630 are fluidly connected by a conduit 1640 that extends throughand between pump connector 1620, plunger housing 1610 and sealing collar1630. A tongue 1650 with a centrally disposed groove or channel 1660 isdisposed within and extends from sealing collar 1630. Tongue 1650 ismolded with valve body 1600 at the juncture of open-ended plungerhousing 1610 and sealing collar 1630. While tongue 1650 is centrallypositioned within sealing collar 1630, it does not block or obstructconduit 1640.

Valve body 1600 is formed from a material compatible with the materialused to form first film 1000 and second film 1200 (e.g., low densitypolyethylene), to enable the valve body to be sealed thereto. Valve body1600 may be formed from any material that enables the valve body to besealed or bonded to the films of the inflatable bladder in a fluid-tightmanner.

With reference now to FIG. 17, a partial plan view of inflatable bladder1540 is shown. To attach valve body 1600 to inflatable bladder 1540, aportion of sealed perimeter 1520 and neighboring inflatable compartment1510 is cut away, as shown at 1710. Ideally, inflatable compartment iscut away at an area that corresponds in width to the tongue and sealingcollar of the valve body. As shown in FIG. 17, inflatable compartment1510 has been cut across its width to form a fluid inlet 1720 into theinflatable compartment. To attach valve body 1600 to the inflatablebladder, and as shown in FIG. 18, a removablepolytetrafluoroethylene/fiberglass cloth strand 1810 is inserted intovalve body 1600 to create a positive air channel during sealing of thevalve body to the inflatable bladder (to be discussed in more detailbelow). Valve body 1600 with cloth strand 1810 is inserted into the openend of plunger housing 1610 and thread through conduit 1640 to sealingcollar 1630. From sealing collar 1630, cloth strand 1810 is fed alongthe length of tongue 1650 and over centrally disposed channel 1660.Tongue 1650 (with cloth strand 1810 over centrally disposed channel1660) is then fed into now cut-open fluid inlet 1720, such that thetongue and cloth strand are situated within a length of inflatablecompartment 1510, an upper portion 1820 of sealing collar 1630 is incontact with second film 1200, and a lower portion 1830 of sealingcollar 1630 is in contact with first film 1000. Inflatable bladder 1540,with valve body 1600 and cloth strand 1810 inserted therein, is then putinto top and bottom heated sealing dies, which are pressed closed toapply heat and pressure to only the edges of the upper and lowerportions of sealing collar 1630 to bond or seal the sealing, collar (andthus the valve body) to the first and second films of the inflatablebladder. It should be noted that holding fixtures andpolytetrafluoroethylene/fiberglass cloths may be employed to protect thevalve body from contact with the heated sealing dies, which could resultin melting or degradation of the valve body. Although the sealing collaris now sealed or bonded to the first and second films of the inflatablebladder, cloth strand 1810 prevents the second or upper film of theinflatable bladder from bonding to tongue 1650 adjacent to cloth strand1810 or centrally disposed channel 1660.

Following the application of heat and pressure to the sealing collar,the inflatable bladder and holding fixtures are moved to a cooling diestation. The cooling dies may have a silicone sponge insert that appliessoft compliant pressure to the seal of the valve body, to maintain thevalve seal shape. When valve body seal has cooled, cloth strand 1810 isremoved from conduit 1640 of valve body 1600 to provide for an openfluid conduit between the structure of the valve body and the interiorof the inflatable bladder compartment, to allow for the ingress andegress of air (fluid) from the inflatable bladder. Following removal ofcloth strand 1810, a conventional valve plunger 1910 and spring arepress-fit (by a manually operated arbor press) into plunger housing 1610of valve body 1600 (FIG. 19). To complete formation of the inflation anddeflation device, a digital ball pump 1920 with an open-ended stem 1940is affixed to the valve body 1600.

Obviously, other inflation and deflation devices known in the art may befluidly connected to the inflatable bladder manufactured by the methodof FIG. 9, including but not limited to those discussed in paragraphs[0065] et al. herein.

It is also contemplated that films 1000 and 1200 of the method of FIG. 9need not be a single ply of material. Indeed, either or both of thefilms may be a laminate of a polymer material and a substrate (of one ormore layers) applied to only one side of the polymer layer (permittingthe opposite side of the polymer layer to be bonded to the second film(or laminate)). Examples of fabrics or other substrates that could belaminated to the films of the method of FIG. 9 include non-wovenmaterials, polyester knits, nylon films, polyester films such asbiaxially-oriented polyethylene terephthalate film, and those materialsdisclosed in paragraph [0038] herein. In some embodiments, either orboth films 1000 and 1200 can include a high melting point layer ofpolymer material and a low melting point layer of polymer material. Forexample, both films 1000 and 1200 can include a high melting point layerand a low melting point layer and the method of FIG. 9 can be performedby disposing a barrier material between the low melting point layers offilms 1000 and 1200 and applying heat and pressure to adhere the lowmelting point layer of film 1000 to the low melting point layer of film1200 except in the vicinity of the barrier material.

It is further envisioned that the method of FIG. 9 could be madecontinuous or semi-continuous similar to the method of FIG. 1. Forexample, and similar to the process of FIG. 7 described herein, therelease coating of the method of FIG. 9 could be continuously “printed”on a web or roll of first film laminate of a polymer material and asubstrate to allow for the continuous and efficient application of therelease coating to the polymer material of the film laminate. Similarly,the first film laminate of the method (with the applied release coating)could be positioned adjacent to a second film laminate of a polymermaterial and heat and pressure applied to adhere the polymer materialsof the laminates except in the vicinity of the release coating. In someinstances, the substrates are materials of substantially higher meltingpoints than the polymer materials such that the substrates do not softenduring the application of heat and pressure. In some embodiments, one orboth of the substrates of the laminates are textured and are not smooth.In example embodiments, the substrate is a smooth or textured polyesterfilm such as biaxially-oriented polyethylene terephthalate film (e.g.,Mylar® film) or the like. One, both, or neither of the substrates can besubsequently removed from the adhered layers. In an alternative example,and similar to the process of FIG. 7 described herein, the releasecoating of the method of FIG. 9 could be continuously “printed” on a webor roll of first film laminate of a polymer material. The first filmlaminate (with the applied release coating) could be positioned adjacentto a second film of a polymer material, the films fed between two pliesof material (e.g., continuous rolls of cloth or other texturedsurfaces), and heat and pressure applied to the plies to adhere thepolymer materials of the laminates except in the vicinity of the releasecoating.

It should be appreciated that while the method of FIG. 9 has beendescribed in connection with inflatable bladders for footwear, the stepsthereof are equally applicable to the formation of inflatable bladdersfor any article of manufacture. Indeed, the methods of FIGS. 1 and 9provide for the formation of inflatable bladders that are high-quality,customizable or easily-modified in configuration, inexpensive and simpleto manufacture, and easily assembled into the article of manufacture forwhich the inflatable bladder is intended.

Another embodiment of a method for manufacturing an inflatable bladderis shown in FIG. 20. With reference to FIG. 20, the method comprises thesteps of: 20(a) positioning a barrier material between a first film anda second film in a configuration corresponding to the shape of aninflatable compartment of an inflatable bladder, 20(b) positioning thefirst and second films with the barrier material positionedthereinbetween between a first ply of material and a second ply ofmaterial, 20(c) adhering the first film to the second film, except inthe vicinity of the barrier material to form an inflatable bladderhaving an inflatable compartment surrounded by a sealed, continuouslysubstantially flat perimeter, and 20(d) removing the first and secondplies of material from the inflatable bladder. One or more of thematerials and/or techniques described herein in connection with themanufacturing methods of FIGS. 1 and 9 may be employed individually orin combination in the steps of the method of FIG. 20. For example, thebarrier material of Step 20(a) may be a curable release coating aspreviously described. In such an embodiment, the positioning step ofStep 20(a) may further comprise the substeps of applying the releasecoating to the first film, curing the release coating to the first film,and sandwiching the cured release coating between the first film and thesecond film. The release coating could be applied to the first filmusing a screen, template, stencil or other technique disclosed herein.The release coating could be cured by the application of ultra violetlight or by other curing means disclosed herein. The first and secondplies of material may be textured and could be formed frompolytetrafluoroethylene-coated, fiberglass-reinforced cloths or anyother suitable material described herein. Adhering Step 20(c) of themethod could be accomplished by rotary lamination, by heated pressingbetween platens, by application of vacuum and heat, or by any otheradhering technique described herein. A suitable inflation device anddeflation device could also be coupled to the inflatable bladder toallow, respectively, for the introduction and release of fluid (e.g.,air) from the inflatable bladder. The inflatable bladder formed by themethod of FIG. 20 may be suitable for incorporation into any article ofmanufacture (including, but not limited to, footwear or other athleticgear), and may be cut to size to facilitate the same in accordance withthe techniques disclosed herein.

Further, in some inflatable articles of manufacture (e.g., footwear orprotective vests), the inflatable bladder needs to bend to accommodatemovement of the wearer or other functionality, and with certaininflatable bladder configurations, this can cause pinching or blockageof a fluid (e.g., air) passage within the bladder, to prohibit completeinflation or deflation thereof. A novel solution to this problem is totexturize the interior surface of the bladder. In one embodiment of thepresent invention, this may be accomplished using a variety oftechniques including by texturing the interior surface of one or both ofthe films of the bladder. In another technique, a release coating isapplied to the interior surface of one of the films in a patterncorresponding to the configuration of the inflatable bladder, while adiscontinuous coating is applied to the interior surface of the otherfilm. The discontinuously applied release coating layer could be apattern of dots, lines, or other shapes that lend texture to theinterior surface of the film to assist in keeping the fluid channels ofthe bladder open. The area of the discontinuously applied layer devoidof release coating could be oriented in the anticipated primarydirection of fluid flow. Alternatively, both of the interior surfaces ofthe bladder films could have a discontinuously applied release coatinglayer, such that the release coating layer applied to one film overlapswith the release coating layer applied to the other film, permitting therelease coating layers to work together to prevent adherence of thefilms to produce the desired inflatable compartment. In still otherembodiments, a barrier material such as foil, paper, or fabric may beused in the vicinity of an anticipated bend in the inflatable bladder tohelp keep the fluid channel open in that area. It should be realized bythose skilled in the art that the afore-described texturizing techniquesmay be employed with any of the methods described in FIG. 1, 9, or 20,or with any other method disclosed herein and/or contemplated by theconcepts and spirit of the present invention.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the invention that others can, by applyingthe knowledge within the skill of the relevant art (including thecontents of the references cited herein), readily modify and/or adaptfor various applications such specific embodiments, without undueexperimentation, without departing from the general concept and spiritof the present invention. Therefore, such adaptations and modificationsare intended to be within the meaning and range of equivalents of thedisclosed embodiments, based on the teaching and guidance presentedherein. It is to be understood that the phraseology or terminology usedherein is for the purpose of description and not of limitation, suchthat the terminology or phraseology of the present specification is tobe interpreted by the skilled artisan in light of the teachings andguidance presented herein, in combination with the knowledge of one ofordinary skill in the art.

What is claimed is:
 1. An article of footwear comprising: (a) a sole;and (b) an upper attached to said sole, said upper including aninflatable bladder, said inflatable bladder comprising: (i) a firstfilm; (ii) a release agent applied and cured to said first film in apattern that corresponds to the shape of an inflatable compartment ofsaid inflatable bladder; and (iii) a second film adhered to said firstfilm such that said release agent is disposed between said first filmand said second film, and said first film and said second film do notadhere in the vicinity of the release agent thereby forming saidinflatable compartment with a peripheral edge, wherein said inflatablebladder is devoid of raised weld lines or raised adhering seams andwherein at least a portion of the exterior surface of said inflatablebladder is textured.
 2. The article of footwear of claim 1, whereinsubstantially all of said exterior surface of said inflatable bladder istextured.
 3. The article of footwear of claim 2, wherein said texturedexterior surface of said inflatable bladder corresponds to the textureof a ply of textured material that was positioned adjacent to saidexterior surface of at least one of said first film or said second filmwhile said first and second films were adhered to each other.
 4. Thearticle of footwear of claim 3, wherein said ply of material is apolytetrafluoroethylene-coated, fiberglass-reinforced cloth.
 5. Thearticle of footwear of claim 1, wherein said inflatable bladder includesa substantially flat, adhered attachment margin extending from saidperipheral edge of said inflatable compartment to an edge of saidinflatable bladder, to facilitate attachment of said inflatable bladderto said upper of the article of footwear.
 6. The article of footwear ofclaim 1, wherein said release agent is silicone fortified and cured bythe application of ultra violet light.
 7. The article of footwear ofclaim 1, wherein at least one of said films is a polymer layer bonded toa substrate.
 8. The article of footwear of claim 1, further comprisingan inflation device and a deflation device.
 9. An article of footwearcomprising: (a) an upper; (b) a sole attached to said upper; and (c) aninflatable bladder attached to the article of footwear, said inflatablebladder comprising: (i) a first single-layered film having an innersurface and a textured outer surface; (ii) a release agent applied andcured to said inner surface of said first single-layered film in apattern that corresponds to the shape of an inflatable compartment ofsaid inflatable bladder; (iii) a second single-layered film having aninner surface and a textured outer surface disposed in facingrelationship with and adhered to said first single-layered film suchthat said release agent is disposed between said inner surface of saidfirst single-layered film and said inner surface of said secondsingle-layered film, said release agent preventing said firstsingle-layered film from adhering to said second single-layered film inthe area where said release agent is applied to form said inflatablecompartment of said inflatable bladder.
 10. The article of footwear ofclaim 9, wherein the texture of said textured outer surfaces of saidfirst and second single-layered films is imparted thereto by a wovenmaterial disposed adjacent to said outer surfaces of said first andsecond single-layered films during adherence of said firstsingle-layered film to said second single-layered film.
 11. The articleof footwear of claim 9 further comprising an inflation device and adeflation device.
 12. The article of footwear of claim 9, wherein saidrelease agent is silicone fortified and cured by the application ofultra violet light.
 13. An article of footwear comprising: (a) aninflatable bladder, said inflatable bladder comprising: (i) a firstfilm; (ii) a release agent applied and cured to said first film in apattern that corresponds to the shape of an inflatable compartment ofsaid inflatable bladder; and (iii) a second film adhered to said firstfilm such that said release agent is disposed between said first filmand said second film, and said first film and said second film do notadhere in the vicinity of the release agent thereby forming saidinflatable compartment with a peripheral edge, wherein said inflatablebladder is devoid of raised weld lines or raised adhering seams andwherein at least a portion of the exterior surface of said inflatablebladder is textured.
 14. The article of footwear of claim 13, whereinsubstantially all of said exterior surface of said inflatable bladder istextured.
 15. The article of footwear of claim 14, wherein said texturedexterior surface of said inflatable bladder corresponds to the textureof a ply of textured material that was positioned adjacent to saidexterior surface of at least one of said first film or said second filmwhile said first and second films were adhered to each other.
 16. Thearticle of footwear of claim 15, wherein said ply of material is apolytetrafluoroethylene-coated, fiberglass-reinforced cloth.
 17. Thearticle of footwear of claim 13, wherein said inflatable bladderincludes a substantially flat, adhered attachment margin extending fromsaid peripheral edge of said inflatable compartment to an edge of saidinflatable bladder, to facilitate attachment of said inflatable bladderto the article.
 18. The article of footwear of claim 13, wherein saidrelease agent is silicone fortified and cured by the application ofultra violet light.
 19. The article of footwear of claim 13, wherein atleast one of said films is a polymer layer bonded to a substrate. 20.The article of footwear of claim 13 further comprising an inflationdevice and a deflation device.